1. Field of the Invention
This invention relates to slide fasteners, more particularly a water-tight slide fastener.
2. Prior Art
There are known a variety of water-tight slide fasteners, a typical example of which is disclosed in Japanese Laid-Open Patent Publication No. 59-108502. Such prior art slide fasteners are rendered water-tight, to prohibit entry of water into an article to which the slide fastener is applied, by coating one or both surfaces of the fastener tapes with a suitable water-resistant or repellant coating material and further by maintaining the confronting edges of the opposed tapes in intimate abutting, sealing contact with each other when the fastener is closed.
However, the prior art water-tight slide fastener has a drawback in that due to tight sealing closure of the confronting tape edges, the slider is subject to increased sliding resistance and would often become sluggish, if not impossible, in its reciprocating movement to open or close the fastener. Another drawback is found in that the fastener when subjected to severe lateral pull is apt to lose its sealing effect at the junction of the two opposed tape edges along which rows of coupling elements are mounted.